'Rectangles with Dominoes' printed from http://nrich.maths.org/

Why do this
problem?

This activity is good for introducing pupils to the exploration
of spatial mathematics. It allows the pupils some degree of freedom
as to how they approach it and record their findings.

Possible approach

Using something bigger than dominoes like giant lego (or just
large dominoes) and initially introducing the challenge altogether
will help learners 'get into' the problem. Pupils can then be left
to find other rectangles, perhaps in pairs.